Although delivered three years after the Aegean Tower opposite it, the Adria Tower is its twin sister. The triangular design, flanked by a trapezoid at the rear, is identical, as are the surface area and height. Only the exterior finish has been modified. The white originally planned has been replaced by a darker stone. The Aegean and Adria thus form a gigantic gateway whose layout, on either side of the central mall of the Faubourg de l'Arche, provides a sufficient view of the Grande Arche, the CNIT, and the esplanade. The building's sobriety is tempered by the presence of sculptures by Igor Mitoraj at its base.

It was in 1995 that Agence Conceptua, founded by Michel Andrault (1926) and Nicolas Ayoub, made its debut in La Défense. The two architects, one a leading figure in French architecture known for having designed several master plans for the business district and the other co-designer of the Société Générale towers in 1995, launched their first project: the KPMG building (now Le Belvédère).

They then focused on the main buildings in the Faubourg de l'Arche district: the Cèdre tower, the Égée tower, and the Adria tower.